Fig. 4: Schematic diagram of ocean’s biological carbon pump and climate change during ancient hyperthermals.
From: Microbial metabolism amplified warming in three Phanerozoic hyperthermal events

a Ocean’s biological carbon pump processes during the pre-CIE phase. b A potential reduction in carbon sequestration by biological carbon pump serves as positive feedback to global warming triggered by massive carbon emission. CIE carbon isotope excursion; DIC dissolved inorganic carbon; POC particulate organic carbon.